//import java.util.Arrays;
public class avg {
    public static double avg(int[] a) {
        int ret = 0;
        double sum;
        for (int x : a) {
            ret += x;
        }
        sum = ret / a.length;
        return sum;
    }
    public static void main(String[] args) {
        int[] array = {1,4,5,6,7,7,8};
        System.out.println(avg(array));
    }
}
